With Corey Tropp out 5-6 weeks with a broken jaw and Marcus Foligno nursing an upper-body strain that will likely keep him out of the lineup until the season opener in Detroit on Oct. 2, the Buffalo Sabres were dealt another blow on Thursday.

Rookie right wing Joel Armia is out indefinitely with a broken hand, Sabres coach Ron Rolston said after the team’s practice at First Niagara Center. It’s still not clear if surgery will be required, but Rolston predicted he’ll be out at least 4-6 weeks.

The injury occurred when Armia, Buffalo’s first-round pick in 2011 (16th overall), was slashed in the second period during the Sabres’ 3-0 win over Columbus on Wednesday.

“Each game was saw improvement in how he’s performing and I thought last night was one of his best games of the exhibition season. He was doing a good job,” Rolston said.

Cody McCormick, who injured his hand in the game on Sunday, will be available to play Friday in Carolina for the team’s final preseason game. Foligno skated after practice in a red non-contact jersey.

The practice on Thursday was also the first time the Sabres worked on special teams on the ice this training camp. The team scored on a delayed penalty against the Blue Jackets and killed off all seven of Columbus’ power plays.

“That’s exactly what today was all about was practicing at length on our power play, on our special teams. It needs work. It can always improve,” Sabres forward Steve Ott said. “You want to start off strong at the beginning of the season and having the chemistry early and practicing hopefully makes some dividends for the start of the year.”

Ott was on the ice during that 6-on-5 delayed penalty goal when the Sabres were able to move the puck confidently and efficiently, waiting for the right shot. Eventually, after about 45 seconds, Ville Leino put home a rebound from Cody Hodgson, giving the Sabres a 1-0 lead.

“It was a really fun sequence to be in. Guys were moving the puck, we had good support. Guys were driving to the lanes, things that instinctively took over for us in last night’s game since it hasn’t been practiced yet,” Ott said. “But we’ve all been in those situations in our careers and in our lives and I think it took over last night. Hopefully when we get those opportunities 6-on-5 we can bury some this year.”